This invention relates in general to certain new and useful improvements in mattresses having liquid containing internal chambers and the method of making the same, and more particularly, to mattresses of the type stated which include an upper liquid chamber which is surrounded by a lower material containing chamber but which permits the upper chamber to be substantially contiguous with the upper surface of the mattress.
In recent years, water beds have become widely commercially acceptable and have found substantially increased use. It has now been fairly well recognized that water beds, that is those forms of beds which employ a water filled mattress, have not only enjoyment value, but therapeutic value as well. In general, it has been found that many people find that it is not only more enjoyable, but is more restful to sleep on a water bed mattress than other forms of conventional mattresses filled with solid, but nevertheless, resilient, material.
The present commercially available water bed mattresses generally comprise a rectangular shell formed primarily of some form of a fairly flexible plastic material and which is filled with water. This form of water bed mattress is thereupon supported in, and by virtue of its construction is required to be supported in, a rigid frame.
In recent years, there have been various other forms of water bed mattresses which include an air frame peripherally surrounding a water bladder, as for example in the Penn et al. U.S. Pat. No. 3,778,852, and the Pennington et al. U.S. Pat. No. 3,787,907. This latter form of water bed mattress, which includes a surrounding air frame, is typically referred to as an air frame water bed mattress. These air frame mattresses differ substantially from the pure water bed mattress, without the air frame, in that those mattresses including the air frame do not require the employment of a rigid structural frame.
The presently available water bed mattresses which do not include the air frame suffer from a large number of deficiencies such as the fact that these mattresses do not obviate the problem of wave action created in the water in the water chamber due to a sudden localized force. Consequently, when a person lies upon a water bed mattress without the surrounding air frame, the water shifts substantially, thereby creating substantial wave action and also the attendant displacement of the surface contour of the mattress.
The other forms of water bed mattresses including the air frame surrounding the water bladder, as exemplified by the Penn et al. Patent and the Pennington et al. Patent mentioned above, also suffer from a number of substantial disadvantages. It has again been well established that those water beds which include the surrounding air frame and which avoid the necessity of a rigid frame do not provide the required degree of comfort. It has been theorized that these water bed mattresses eliminate some of the wave action which is created by a sudden localized force. Nevertheless, it is also well established that the air bladder is relatively incompressible with respect to the water bladder. Consequently, the water bed mattresses which include the surrounding air frame do not provide constant and adequate support. The same generally holds true of those water bed mattresses which do not employ the air frame surrounding the water bladder. One of the primary problems of each of these conventional water beds is that they do not provide equal water flotation with respect to the entire upper surface of the water bed mattress.
Another important disadvantage with respect to the water bed mattresses of each of the aforementioned types is that they are not constantly sized with respect to a supporting structure or, otherwise, a supporting frame. Consequently, difficult often arises in fitting the water bed mattress, when filled with water, or otherwise with water in the water bladder and air in the air bladder, to the supporting frame or a supporting structure.
The present invention obviates these and other problems in the provision of a fluid containing mattress which includes a pair of upper and lower sheets having peripherally extending, perpendicularly struck side wall flaps. These side wall flaps are secured to each other in order to form an outer peripheral end wall, thereby defining a rectangularly shaped water bed mattress section forming an inner liquid chamber. In this way, the inner liquid chamber is established between the upper sheet, the lower sheet and the outer peripheral wall. Moreover, a material chamber is formed beneath the liquid chamber at least along the periphery thereof. This material chamber may be filled with a suitable material as hereinafter described and, when filled, surrounds at least the periphery of the liquid chamber along the lower sheet thereof and in adjacent relationship to the lower sheet and the inner peripheral end wall. In accordance with this construction, the liquid chamber is substantially contiguous with the upper sheet so that a person lying on the mattress is completely supported by the liquid chamber with constant flotation. Nevertheless, the lower material filled chamber contains air or another material which renders it essentially more rigid and surrounds at least the outer portion of the entire mattress, although the party lying on the mattress does not actually contact the lower material chamber section.